Troubleshooting Logstashedit

Installation and setupedit

Inaccessible temp directoryedit

Certain versions of the JRuby runtime and libraries in certain plugins (the Netty network library in the TCP input, for example) copy executable files to the temp directory. This situation causes subsequent failures when /tmp is mounted noexec.

Sample error

[2018-03-25T12:23:01,149][ERROR][org.logstash.Logstash ]
java.lang.IllegalStateException: org.jruby.exceptions.RaiseException:
(LoadError) Could not load FFI Provider: (NotImplementedError) FFI not
available: java.lang.UnsatisfiedLinkError: /tmp/
/tmp/ failed to map segment from shared object:
Operation not permitted

Possible solutions

  • Change setting to mount /tmp with exec.
  • Specify an alternate directory using the setting in the jvm.options file.

Logstash start upedit

Illegal reflective access errorsedit

Running Logstash with Java 11 results in warnings similar to these:

WARNING: An illegal reflective access operation has occurred
WARNING: Illegal reflective access by org.jruby.ext.openssl.SecurityHelper (file:/{...}/jruby{...}jopenssl.jar) to field
WARNING: Please consider reporting this to the maintainers of org.jruby.ext.openssl.SecurityHelper
WARNING: Use --illegal-access=warn to enable warnings of further illegal reflective access operations
WARNING: All illegal access operations will be denied in a future release

These errors appear related to a known issue with JRuby.

Work around

Try adding these values to the jvm.options file.



  • These settings allow Logstash to start without warnings in Java 11, but they prevent Logstash from starting on Java 8.
  • This workaround has been tested with simple pipelines. If you have experiences to share, please comment in the issue.

Troubleshooting persistent queuesedit

Symptoms of persistent queue problems include Logstash or one or more pipelines not starting successfully, accompanied by an error message similar to this one.

message=>" Page file size is too small to hold elements"

See the troubleshooting information in the persistent queue section for more information on remediating problems with persistent queues.

Data ingestionedit

Error response code 429edit

A 429 message indicates that an application is busy handling other requests. For example, Elasticsearch sends a 429 code to notify Logstash (or other indexers) that the bulk failed because the ingest queue is full. Logstash will retry sending documents.

Possible actions

Check Elasticsearch to see if it needs attention.

Sample error

[2018-08-21T20:05:36,111][INFO ][logstash.outputs.elasticsearch] retrying
failed action with response code: 429
({"type"=>"es_rejected_execution_exception", "reason"=>"rejected execution of
org.elasticsearch.transport.TransportService$7@85be457 on
EsThreadPoolExecutor[bulk, queue capacity = 200,
pool size = 16, active threads = 16, queued tasks = 200, completed tasks =


For general performance tuning tips and guidelines, see Performance Tuning.

Troubleshooting a pipelineedit

Pipelines, by definition, are unique. Here are some guidelines to help you get started.

  • Identify the offending pipeline.
  • Start small. Create a minimum pipeline that manifests the problem.

For basic pipelines, this configuration could be enough to make the problem show itself.

input {stdin{}} output {stdout{}}

Logstash can separate logs by pipeline. This feature can help you identify the offending pipeline. Set pipeline.separate_logs: true in your logstash.yml to enable the log per pipeline feature.

For more complex pipelines, the problem could be caused by a series of plugins in a specific order. Troubleshooting these pipelines usually requires trial and error. Start by systematically removing input and output plugins until you’re left with the minimum set that manifest the issue.

We want to expand this section to make it more helpful. If you have troubleshooting tips to share, please:

Logging level can affect performancesedit


Simple filters such as mutate or json filter can take several milliseconds per event to execute. Inputs and outputs might be affected, too.


The different plugins running on Logstash can be quite verbose if the logging level is set to debug or trace. As the logging library used in Logstash is synchronous, heavy logging can affect performances.


Reset the logging level to info.